Expansive Soil in Oklahoma: County Ratings
23 of the 77 rated counties in Oklahoma have a dominant shrink-swell rating of High or Very High. Each rating below is the NRCS shrink-swell class covering the largest share of the county's mapped soil acres, computed from USDA SSURGO data. Open a county for the full class breakdown and what it means for a slab foundation.
| County | Dominant class | High + Very High share | Survey coverage |
|---|---|---|---|
| Adair County | Low | 24% | 100% |
| Alfalfa County | Low | 9% | 98% |
| Atoka County | High | 52% | 98% |
| Beaver County | Low | 7% | 100% |
| Beckham County | Low | 10% | 99% |
| Blaine County | Low | 18% | 98% |
| Bryan County | High | 47% | 95% |
| Caddo County | Low | 7% | 99% |
| Canadian County | Moderate | 22% | 98% |
| Carter County | Moderate | 24% | 98% |
| Cherokee County | Low | 26% | 96% |
| Choctaw County | High | 51% | 95% |
| Cimarron County | Low | 17% | 99% |
| Cleveland County | Low | 20% | 96% |
| Coal County | High | 70% | 99% |
| Comanche County | Moderate | 36% | 97% |
| Cotton County | High | 56% | 98% |
| Craig County | High | 50% | 100% |
| Creek County | Low | 38% | 98% |
| Custer County | Low | 0% | 99% |
| Delaware County | Low | 6% | 93% |
| Dewey County | Low | 2% | 99% |
| Ellis County | Low | 3% | 100% |
| Garfield County | High | 55% | 100% |
| Garvin County | Low | 38% | 98% |
| Grady County | Low | 10% | 99% |
| Grant County | High | 55% | 100% |
| Greer County | Low | 24% | 98% |
| Harmon County | Low | 28% | 98% |
| Harper County | Low | 3% | 100% |
| Haskell County | High | 57% | 92% |
| Hughes County | Low | 20% | 98% |
| Jackson County | Moderate | 29% | 97% |
| Jefferson County | Moderate | 8% | 97% |
| Johnston County | Moderate | 23% | 97% |
| Kay County | High | 60% | 97% |
| Kingfisher County | Moderate | 22% | 99% |
| Kiowa County | High | 53% | 98% |
| Latimer County | High | 67% | 99% |
| Le Flore County | High | 43% | 99% |
| Lincoln County | Low | 26% | 99% |
| Logan County | Low | 21% | 98% |
| Love County | Low | 19% | 96% |
| Major County | Low | 11% | 99% |
| Marshall County | Low | 46% | 86% |
| Mayes County | Low | 32% | 95% |
| McClain County | Low | 15% | 98% |
| McCurtain County | High | 58% | 97% |
| McIntosh County | High | 44% | 86% |
| Murray County | Moderate | 34% | 97% |
| Muskogee County | High | 54% | 96% |
| Noble County | Moderate | 44% | 98% |
| Nowata County | Moderate | 39% | 97% |
| Okfuskee County | Low | 38% | 98% |
| Oklahoma County | Low | 26% | 91% |
| Okmulgee County | Low | 32% | 98% |
| Osage County | High | 55% | 97% |
| Ottawa County | High | 43% | 95% |
| Pawnee County | High | 56% | 94% |
| Payne County | Low | 33% | 97% |
| Pittsburg County | High | 71% | 95% |
| Pontotoc County | Moderate | 29% | 99% |
| Pottawatomie County | Low | 21% | 98% |
| Pushmataha County | Low | 11% | 98% |
| Roger Mills County | Low | 0% | 100% |
| Rogers County | Moderate | 43% | 93% |
| Seminole County | Low | 29% | 97% |
| Sequoyah County | Low | 12% | 94% |
| Stephens County | Low | 16% | 98% |
| Texas County | Moderate | 7% | 100% |
| Tillman County | High | 47% | 98% |
| Tulsa County | High | 46% | 95% |
| Wagoner County | High | 41% | 94% |
| Washington County | Moderate | 45% | 96% |
| Washita County | Low | 2% | 100% |
| Woods County | Low | 21% | 99% |
| Woodward County | Low | 15% | 99% |
How these ratings are computed
Ratings come from USDA NRCS SSURGO soil survey data: for each soil component we take the maximum linear extensibility percent (lep_r) in the top 100 cm, apply the NRCS Handbook Part 618 class limits (Low under 3 percent, Moderate 3 to 6, High 6 to 9, Very High 9 and above), assign map units by plurality of component percent, and roll acres up to the county. Full details on the methodology section of the lookup page. A county rating is not a parcel-level geotechnical assessment.